中文摘要：

目的观察何首乌有效成分二苯乙烯苷（TSG）在体外实验中对a-突触核蛋白（d—synuclein，a-Syn）过表达的影响及其作用机制。方法不同浓度的TSG与d—Syn基因转染PCI2细胞共孵育24h，应用噻唑蓝（MTr）法和乳酸脱氢酶漏出法确定该药对培养细胞的无毒范围，RT—PCR法检测细胞中d—SynmRNA含量的变化，蛋白质印迹（Western blotting）法检测d—Syn、泛素化蛋白羧基端水解酶（UCH—L1）和parkin蛋白的表达，观察TSG对它们的影响。结果TSG对培养细胞的无毒范围为6．25～100umol·L^-1。在此剂量范围内的TSG与a-Syn基因转染PCI2细胞孵育24h，能够明显减少模型细胞a-SynmRNA含量，抑制a-Syn蛋白表达和聚集，增强UCH—L1和parkin蛋白表达。结论TSG在体外对基因转染细胞的OL—Syn过表达和聚集有明显抑制作用，其作用机制与抑制d—Syn合成和增强d—Syn降解有关。

英文摘要：

OBJECTIVE To explore the effects and mechanisms of 2,3,5,4＇-tetrahydroxy stilbene-2-13-D- glycoside （TSG）, an ef- fective component of Polygonum multiflorum, on a-synuelein （a-Syn） over-expression in vitro. METHODS Different concentrations of TSG were incubated with a-Syn gene-transfeeted PC12 cells for 24 h. The nontoxicity range of TSG to cultured cells was determined by MTT method and lactate dehydrogenase leakage method. The change in oL-Syn mRNA content in the cells was measured by RT-PCR. The protein expression of a-Syn, UCH-L1 and parkin was detected by Western blotting. RESULTS The nontoxieity range of TSG to cultured cells was 6. 25 - 100 μmol·L^-1. When incubated with a-Syn gene-transfected PC12 ceils within this dose range for 24 h, TSG significantly decreased oL-Syn mRNA content, inhibited a-Syn protein expression and aggregation, and enhanced the protein expression of UCH-L1 and parkin in the model cells. CONCLUSION TSG inhibited a-Syn over-expression and aggregation in gene-tranfected PC12 cells in vitro, and the mechanisms may be related to the inhibition of synthesis and the enhancement of degradation of a-synuclein.